“Science progresses by trial and error, by conjectures and refutations. Only the fittest theories survive.”

Darwinism:
That survivors survive.
Source: The Book of The Damned (1919), Ch. 3, part 1 at resologist.net

Source: What Is This Thing Called Science? (Third Edition; 1999), Chapter 5, Introducing falsification, p. 67.

conjecture <br class="br">in his Nobel Lecture http://nobelprize.org/nobel_prizes/chemistry/laureates/1996/curl-lecture.html, December 7, 1996, Dawn of the Fullerenes: Experiment and Conjecture

Axelrod, Robert, and William Donald Hamilton. "The evolution of cooperation." Science 211.4489 (1981): 1390

Source: Manhood of Humanity (1921), p. 136. Chapter: Capitalistic Era.
Context: Such as contribute most to human progress and human enlightenment — men like Gutenberg, Copernicus, Newton, Leibnitz, Watts, Franklin, Mendeleieff, Pasteur, Sklodowska-Curie, Edison, Steinmetz, Loeb, Dewey, Keyser, Whitehead, Russell, Poincaré, William Benjamin Smith, Gibbs, Einstein, and many others — consume no more bread than the simplest of their fellow mortals. Indeed such men are often in want. How many a genius has perished inarticulate because unable to stand the strain of social conditions where animal standards prevail and "survival of the fittest" means, not survival of the "fittest in time-binding capacity," but survival of the strongest in ruthlessness and guile — in space-binding competition!

Nathan Gore in Ch. IV
Democracy: An American Novel (1880)

United Nations Bulletin Vol. XVI, No. 4 (15 February 1954)

Source: The Selfish Gene (1976, 1989), Ch. 2. The replicators

Dissent, Burnet v. Coronado Oil & Gas Co., 285 U.S. 393 (1932).
Judicial opinions
Context: Stare decisis is usually the wise policy, because in most matters it is more important that the applicable rule of law be settled than that it be settled right... This is commonly true even where the error is a matter of serious concern, provided correction can be had by legislation. But in cases involving the Federal Constitution, where correction through legislative action is practically impossible, this court has often overruled its earlier decisions. The court bows to the lessons of experience and the force of better reasoning, recognizing that the process of trial and error, so fruitful in the physical sciences, is appropriate also in the judicial function.